Al-Muhalla

Kitab al-Muhallā bi'l Athār, also known as Al-Muhalla ("The Sweetened" or "The Adorned Treatise," ) is a book of Islamic law and jurisprudence by Ibn Hazm, a 11th century Sunni Islamic scholar. It is considered one of the primary sources of the Zahirite or literalist school within Sunni Islam.
Description
The book is noted for the author's view that a Muslim is not obliged to fulfill every promise; specifically, that a Muslim who promised to commit a criminal act shouldn't fulfill such a promise.
Reception
It is his commentary on his own al-Mujalla ("The Brilliant Treatise"), and it is considered a masterpiece of fiqh literature.
A site describes it:

This book is a wealth of scholarship, in which Ibn Hazm discusses each question separately. On each question, he cites the views of earlier scholars of high achievement, not restricting himself to the views of the four schools of Fiqh, but also citing the rulings
...